While various types of encapsulants for electronic components have been known and used in the past, it has recently become advantageous to selectively encapsulate certain portions of electronic circuits such as hybrid type integrated circuits, while leaving other portions of the circuit initially free of encapsulant. For example, one may want to encapsulate and protect an active device region of an integrated circuit while leaving selected nonactive regions such as bonding pads or other areas free of encapsulant. Alternatively, as will hereinafter be shown, one may want to selectively apply encapsulant to a hybrid circuit so as to facilitate further processing in a manner which increases the yield and reduces the production cost for manufacturing such circuit.
Because of the proximity of adjacent components on hybrid integrated circuit, and the process steps needed to complete such a circuit, the rheology of encapsulated material is critical, especially where selective encapsulation may be desired. The encapsulant must be fluid enough to be deposited in the selected areas to be encapsulated while not exhibiting flow characteristics which cause it to flow or creep onto areas which are to remain bare. Thus, a delicate balance must be achieved for an encapsulant to be useful for this purpose.